Problem: If $g(x) = 3x + 7$ and $f(x) = 5x - 9$, what is the value of $f(g(8))$?
Solution: $g(8)=3(8)+7=24+7=31$. Thus, $f(g(8))=f(31)=5(31)-9=155-9=\boxed{146}$.